Magnetic overloads typically use which to sense motor current?

Magnetic overloads utilize current coils to sense motor current due to their ability to measure the magnetic field generated by the current flowing through the motor's conductors. When the motor current exceeds a predetermined level, the resulting increase in magnetic field strength acts on a mechanism within the overload protection device, prompting it to trip and disconnect the motor from the power supply.

This type of sensing is highly effective for detecting overcurrent conditions that could lead to motor overheating or damage. The current coil provides a quick and reliable response to changes in motor current, which is essential for protecting electrical equipment from potential faults without relying on slower responses typical of thermal elements.

In contrast, thermal elements respond to heat generated by the current, flux sensors detect changes in magnetic flux linking the motor winding, and capacitive probes measure electrical capacitance, which are not suitable for immediate overcurrent detection. Hence, current coils are the preferred method for accurately sensing motor current in magnetic overloads.